What Is A Sand Battery?
Generally, when one pictures a battery, one imagines the lithium battery(锂电池) in various high-tech forms. Yet in 2022, Polar Night Energy launched the world's first commercial sand battery, capable of storing 500-600℃ in heat energy for months.
With the environmental concern of mining for lithium batteries, investors and companies are looking for alternatives, and sand batteries are one of them. The concept for a sand battery is simple: storing large amounts of heat in sand or sand-like materials for later use. The advantage of sand is its ability to store large amounts of heat in a small volume, its large quantity, and its low cost.
Sand batteries serve as storage for spare wind and solar power and extra energy when demand is low. They can provide heated water as well as heated air to homes and industries that would otherwise use fossil fuels. The heat can also be changed back to electricity using a steam turbine (蒸气涡轮).
This technique dates back centuries. Ancient Egyptian homes were made of sand mixed with mud and straw that would keep the heat of the hot desert sun and then release it slowly during the cool nights. Many native Americans used mud to build houses for the same reason. They would also store heat from campfires in rocks wrapped (包裹) in leather skin and use these rocks for heating their beds at night. This ancient wisdom can now be applied to modern solutions through sand batteries.
Now, Polar Night Energy, working with the heating company Lovisan Lämpð, will launch a sand battery 10 times the size and capable of storing up to100megawatts hour of heat. This battery will eliminate the need for oil-based energy for the entire town of Pornainen; Finland, and keep 160 tonnes of carbon dioxide out of the atmosphere annually. According to the Washington Post, more than $900 million has been invested in clean storage technologies in the past three years, a number that is expected to reach $3 trillion by 2040. This money is being directed towards various small companies that are investigating natural batteries.
There are challenges to overcome before this technology can be adopted widely. It remains to be seen whether natural batteries can be a steady source of energy. Furthermore, because it's an emerging industry, natural battery projects will need to be built from scratch, meaning only developed countries can afford to use them. Despite this, sand and other natural battery solutions are an exciting step forward towards a green future.
